Device for sealing pipelines

ABSTRACT

This inventions relates to a plugging machine and a rigid tube provided with a stationary disc integral with the bottom of the tube and oriented almost orthogonal to the tube, with a movable disc paired with the stationary disc. A sealing ring of a resilient material is located between the discs and compressed when the movable disc is pressed against the stationary disc to adhere to an inner surface of the pipeline. The sealing ring is coaxial with respect to the pipeline. The movement of the movable disc is determined by raising or lowering a control rod within the tube by means of sloping sliders made in the lower portion of the rod which engage in respective grooves, likewise sloping, made in an axial shank associated with the movable disc and sliding inside an axial opening of the stationary disc. A component of a force is generated which is parallel to the axis of the discs. The axis is raised or lowered by rotation of a threaded ring engaging in a threading mate at the top of the rod.

CROSS REFERENCE TO RELATED APPLICATIONS

Non-applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Non-applicable

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Non applicable

REFERENCE TO A SEQUENCE LISTING

Non-applicable

STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINTINVENTOR

Italian Patent Application No. B02013A000345 filed Apr. 7, 2013.

DESCRIPTION OF THE INVENTION

The present invention relates to the technical field concerning theequipment for performing installation, repair and/or maintenanceoperations of pipelines, which carry fluids under pressure, for examplegas, water, hydrocarbons and the like, without interrupting the serviceand avoiding the dispersion of polluting substances in the environment.

In particular, the apparatuses intended to operate on pipelines ofmedium dimensions are taken into consideration, for example thosebelonging to a distribution system, having the diameter of some inches,either below or above ground level, therefore excluding the domesticsystems.

Such apparatuses are known as plugging machines and are installed inpairs, respectively upstream and downstream of the piece of pipeline tobe acted upon, and joined with a temporary pipeline, so as to create aby-pass, into which the flow is deviated without being interrupted.

More in detail, the pipeline is perforated in two selected points, aconnector and valve (called “flat valve” in jargon) are applied to eachof the holes and then the respective plugging machines are fastenedthereto; each of the latter includes a substantially bell-like, mainbody in which a plugging head is housed. The plugging head is lowered,by suitable means, made to pass through the flat valve and connector, soas to enter the underlying pipeline.

In the known solutions, the plugging head is lowered with its axissubstantially orthogonal with respect to the pipeline and then rotatedby 90°, so as to arrange it coaxial with the latter; afterwards, meansare operated to move the two discs, provided at the head, close to eachother. A sealing ring, made of rubber or the like, having for example atrapezoidal cross-section, is interposed between the two discs.

Due to the axial compression, the sealing ring expands radially,adhering strongly to the inner surface of the pipeline, thus making aseal. The passing fluid is forced to deviate within the main body of theplugging machine upstream, then to flow into the temporary pipeline andreach the plugging machine downstream, through which it is reintroducedinto the pipeline via a reverse path.

From a constructive point of view, a plugging machine of known typepresents the maximum complexity in the means which allow and controlinclination of the plugging head. These means must comply, both from thestrictly dimensional point of view and from the functional point ofview, with the means that move the discs, between which the sealing ringis interposed, close and away from each other.

Independently from the mechanical solutions chosen for the abovementioned means and from their bigger or smaller functional validity, itis obviously understood that the strength and reliabilitycharacteristics, which are obtained with considerable dimensions in caseof big plugging machines, cannot be found in plugging machines suitablefor medium dimension pipelines (in proportion to the necessary dimensionreduction, thus to the inner diameter of the pipeline).

In other words, some technical solutions, valid for certaindimensioning, become poor with reduced dimensions.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to propose a device associatedto a plugging machine for sealing pipelines, particularly simple andessential, so as to obviate the principal drawbacks reported by theknown solutions.

Another object of the invention is to obtain a device which isindicated, due to its constructive characteristics, with medium-smalldimensions of the pipelines into which it is to be introduced, forexample, with a diameter of a few inches, and consequently of theplugging machine.

A still further object of the invention is to realize a strong device,which is very rigid, so as not to be adversely affected by the pressureof the fluid and to assure a correct and stable position inside thepipeline, thus an optimal tightness.

A still further object of the invention is to propose a compact device,which is easy to handle due to its limited weight and dimensions, quickto be installed and equally quick to be removed, to limit the total costof the operations that require its use.

These and other objects are wholly obtained by a device for sealing ofpipelines associated with a plugging machine, with the latter being ofthe type designed for the execution of maintenance and/or repairoperations in the pipelines, in which fluids under pressure areconveyed, and aimed at being fastened to a connector made integral andcommunicating with one of the pipelines, perpendicular to its axis, withthe above mentioned device protruding downward from the plugging machineand inserted within the pipeline and including:

-   -   a rigid tube, supported by the body of the plugging machine and        extended therebelow, so as to pass through the connector and        insert into the pipeline with axis almost orthogonal thereto;    -   a stationary disc, integral to the lower end of the rigid tube,        arranged coaxial with the pipeline, provided with an axial        through hole, with which the internal cavity of the same tube is        set in communication and which has a face shaped like a        truncated cone;    -   a movable disc, arranged coaxial with and counter-facing the        stationary disc, with a respective face having a truncated cone        profile symmetrical to that of the face of the stationary disc,        with the movable disc featuring an axial shank adapted to be        inserted slidably in the axial hole of the stationary disc, so        that the mutual distance between them can be adjusted;    -   a sealing ring of elastomeric material, with a trapezoidal        cross-section, interposed between the stationary and movable        discs, the sealing ring having its outer diameter dimension        slightly less than the internal diameter of the pipeline, in        non-operating condition, in which the movable discs are not        compressed axially, with the same stationary and movable discs        mutually moved away, with the above mentioned ring expanding        radially, in operating condition, in a manner as to adhere        sealingly to the inner surface of the same pipeline, as a        consequence of an axial compression exerted by mutual        approaching of the discs;    -   a control rod, slidably inserted in the tube, extended upwards        to come out from the body of the plugging machine and downwards        to abut against the axial shank of the movable disc;    -   drive means, provided between the lower portion of the control        rod and the shank of the movable disc, operated by axial        translation of the rod to make the shank and the movable disc        rigidly coupled therewith, carry out corresponding axial        movements away from or close to the stationary disc, to        determine respectively the non-operating and operating        conditions of the sealing ring;    -   operating means, associated to the upper portion of the control        rod, provided to cause the axial movements of the latter.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention will become evident from thefollowing description of a preferred embodiment of the device forsealing of pipelines under discussion, in accordance with the contentsof the claims and with help of the enclosed figures, in which:

FIG. 1 is a schematic vertical cross-section of a plugging machine,provided with the sealing device under discussion associated to apipeline;

FIG. 2 illustrates, in enlarged scale, the detail H of FIG. 1, to pointout the part of the device inserted in the pipeline, in non operatingposition;

FIG. 3 is a view similar to that of FIG. 2, with the device in operativeposition;

FIG. 4 is a perspective view of a control rod of the device;

FIG. 5 is a cross-section view of a stationary disc of the device and amovable disc to be coupled with the stationary disc, moved away to bebetter pointed out;

FIG. 6 is a perspective view of the movable disc of the previous Figure.

DETAILED DESCRIPTION OF THE INVENTION

The device 1 is provided in connection with a plugging machine 100 ofsubstantially known type shown schematically in FIG. 1.

The plugging machine 100 is intended to be fastened to a connector 110,made integral and communicating with a pipeline 200 that conveys a fluidunder pressure.

The plugging machine 100 is designed to cooperate with a twin machine(not shown) associated with the pipeline 200 to create a by-pass thatisolates a piece of the pipeline without interrupting the flow to allowmaintenance and/or repair operations in the piece.

According to the invention, device 1 includes a rigid tube 2 supportedby a body 101 of the plugging machine 100 and extending therebelow topass through the connector 110 and a flat valve 120 of known typeassociated to the same connector 110. In this way, the tube enters thepipeline 200 with an axis almost orthogonal to that of the latter.

In the non-limiting example shown in the figures, the tube 2 is inclinedwith respect to the condition of perpendicularity by about 4°.

The rigid tube 2 protrudes upwards from the body 101 passing through acollar 102, which assures the tightness against the leaks of the fluidin a known way not shown in detail.

A stationary disc 3 is integral, for example as a single body, with alower end 2B of the rigid tube 2. Due to the positioning of the pluggingmachine 100 on the pipeline 200, the stationary disc 3 is arrangedcoaxial with the latter.

The stationary disc 3 is provided with an axial through hole 30 intowhich the internal cavity 20 of the tube 2 opens. The stationary disc 3has a truncated cone-shaped face 31 opposite to the one facing the tube.

A first annular rim 310 is thus defined in the face 31, the inner partof which slightly protrudes with respect to the outer part.

The stationary disc 3 mates with a movable disc 4, arranged coaxialtherewith, opposite thereto and featuring a face 41 with a truncatedcone profile symmetrical to that of face 31 of the stationary disc 3.

Consequently, a second annular rim 410 is defined in the face 41 of themovable disc 4. An annular groove 5 having a trapezoidal cross-sectionis defined between the second annular rim 410 and the opposite firstannular rim 310. The annular groove 5 houses a sealing ring 50 ofelastomeric material, having a complementary trapezoidal cross-section,in such a way that its sides remain in contact with the first and secondannular rim 310, 410.

The movable disc 4 is provided also with an axial shank 40 adapted torun slidably within the axial hole 30 of the stationary disc 3 so thatthe mutual distance between the discs, and accordingly the width of theannular groove 5, can be adjusted.

The external diameter of the sealing ring 50 is slightly smaller withrespect to the inner diameter of the pipeline 200, in non-operatingcondition R, in which no axial compression is exerted on the discs, thatis when the movable disc 4 is moved away from the stationary disc 3.

The ring 50 can expand radially in operating condition W in a manner asto adhere sealingly to the inner surface of the pipeline 200, due to anaxial compression caused by moving closer of the discs 3, 4.

A control rod 6 is provided to control the movements of the movable disc4 close to or away from the stationary disc 3 from outside of theplugging machine 100. The control rod 6 is introduced slidably into tube2, extended upwards to come out from the body 101 of the machine 100 anddownwards to abut against the axial shank 40 of the movable disc 4.

Drive means 7 are interposed between the lower portion 6B of the controlrod 6 and shank 40 and are, operated by axial translation of the rod 6to make the shank 40 and the integral movable disc 4 carry outcorresponding axial movements away from or closer to the stationary disc3 and to determine respectively the non-operating condition “R” andoperating condition “W” of the sealing ring 50.

The drive means 7 include at least a slider 70 projecting transverselyfrom the control rod 6 and provided with two faces 71, 72 parallel toeach other but sloping with respect to the longitudinal axis of the rod6.

The slider 70 is aimed at engaging in a complementary groove 44 made inthe shank 40 so that the axial thrust exerted on the rod 6, in one orthe other direction, generates a component of a force parallel to theaxis of discs 3, 4, by means of the contact surfaces 71, 72 of theslider 70 and the corresponding surfaces of the groove 44. Thus,according to the direction of this component, axial movements of themovable disc 4 away from or close to the stationary disc 3 are carriedout.

In a preferred embodiment of the drive means 7, two parallel flatsurfaces 60 are made in the lower portion 6B of the rod 6, from whichtwo respective symmetrical sliders 70 protrude.

The shank 40 of the movable disc 4 features a longitudinal slit 42arranged on a median plane of the shank 40, which is thus divided in twoportions.

The facing faces of the slit 42 feature two of the above mentionedmirror-like grooves 44, within which the lower portion 6B of the rod 6can be slidably introduced with its flat surfaces 60, and the twosliders 70 can engage with the corresponding grooves 44.

In order to obtain the movement of the movable disc 4 due to the raisingand lowering of the rod 6, it is necessary that the inclination angle ofthe sliders 70 and the grooves 44 coupled mating therewith is suitablydetermined with respect to the axis of the discs 3, 4. The value of thisangle is comprised between 55° and 60°.

Operating means 8, associated in the upper portion 6A of the control rod6, can determine the axial translations of the rod 6 between two extremepositions corresponding to the non-operating condition “R” and operatingcondition “W” of the sealing ring 50.

In another embodiment, the operating means 8 include a threading 80 madein the upper portion 6A of the control rod 6 and aimed at meshing with athreaded hole 81 made in a screw ring 82, the latter being rotatablysupported by the rigid tube 2 and designed to be manually operated torotate, in one direction or in the other, to raise or lower the controlrod 6.

Advantageously, the device 1 includes also anti-rotational means 9,associated to the rigid tube 2 adapted to stabilize the position of thelatter and of the integral stationary disc 3 in a manner that the axisof the stationary disc 3, as well as the movable disc 4, coincide on ahorizontal plane with that of the pipeline 200.

The anti-rotational means 9 are composed of, for example, a flange 90locked at the upper end 2A of the tube 2 from which a bar 91 protrudesradially and the bar is aimed at introducing in a fork 92 fastened tothe body 101 of the machine 100.

The figures illustrate a technical solution, according to which the bar91 is hinged to the flange 9p to rotate upwards and release from theconstraint of the fork 92. This feature is useful in the installationsteps and removal of the plugging machine 100.

The present invention's simple and essential structure makes it suitablewhen the dimensions of the pipelines, in which it is to be introduced,are medium or medium-small, for example with a diameter of a few inches.

The device according to the invention is strong and very rigid due tothe constructive solution of the tube which is made as a single bodywith the stationary disc.

In this way, a considerable resistance to the pressure exerted by thefluid is obtained and a correct and stable position inside the pipeline,and consequently an optimal tightness can be assured.

A special importance must be given to the conformation of the drivemeans which allow the movable disc to move close to and away from thestationary disc and consequently the sealing ring to be compressed andreleased. The solution of inclined sliders within likewise inclinedgrooves is very simple from a mechanical point of view, and, at the sametime, it is effective in functional terms and extremely compact.

The combination of advantageous characteristics of the invention allowsa compact and easy to handle device to be obtained due to its limitedweight and dimensions, quick to be installed and equally quick to beremoved so as to limit the total cost of the operation.

It is understood, however, that what has been described above isillustrative and not limiting, therefore, possible detail variationsthat could become necessary for technical and/or functional reasons, arefrom now considered within the protective scope as defined in the claimsbelow.

1. A device for the sealing of pipelines, the device being associatedwith a plugging machine provided for the execution of maintenance and/orrepair in said pipelines, through which fluids are conveyed underpressure, and intended to be fixed to a connector (110) made integralwith and communicating with one of said pipelines (200), perpendicularlyto the axis of the latter, with said device (1) protruding downward fromsaid plugging machine (100) and inserted within said pipeline (200),said device comprising: a rigid tube (2), supported by the body (101) ofsaid plugging machine (100) and extended therebelow to pass through saidconnector (110) and insert into said pipeline (200) with axis almostorthogonal thereto; a stationary disc (3), integral to a lower end (2B)of said rigid tube (2), arranged coaxial with respect to said pipeline(200) and featuring an axial through hole (30) to which the internalcavity (20) of the same sleeve (2) is joined and which has a relativeface (31) shaped like a truncated cone; a movable disc (4), arrangedcoaxial with and counter-facing said stationary disc (3), with arespective face (41) having a truncated cone profile symmetrical to thatof the face (31) of the stationary disc (3), with said movable disc (4)featuring an axial shank (40) adapted to be inserted slidably in saidaxial hole (30) of the stationary disc (3), so that the mutual distancebetween them can be adjusted; a sealing ring (50) of elastomericmaterial, with a trapezoidal cross-section, interposed between saidstationary (3) and movable (4) discs, having its outer diameterdimension slightly less than the internal diameter of said pipeline(200), in non operating condition (R) when no axial compression isexerted on said discs, with the stationary (3) and movable (4) discsmutually moved away, said ring (50) being designed to expand radially,in operating condition (W), in a manner as to adhere sealingly to theinner surface of the same pipeline (200), as a consequence of an axialcompression exerted by mutual approaching of said discs (3,4); a controlrod (6), slidably inserted in said tube (2), extended upwards to comeout from said body (101) of the plugging machine (100) and downwards toabut against said axial shank (40) of the movable disc (4); slidingdrive means (7), provided between the lower portion (6B) of said controlrod (6) and said shank (40) of the movable disc (4), operated by axialtranslation of said rod (6) so as to make said shank (40) and themovable disc (4), rigidly coupled therewith, carry out correspondingaxial movements away from or close to said stationary disc (3), so as tocause respectively said non operating (R) and operating (W) conditionsof said sealing ring (50); operating means (8), associated to the upperportion (6A) of said control rod (6), provided to determine said axialmovements of the latter; said sliding drive means (7) include at least aslider (70) projecting transversely from said lower portion (6B) of thecontrol rod (6), and provided with two faces (71, 72) parallel to eachother but sloping to the longitudinal axis of the latter, said slider(70) being intended to engage in a complementary groove (44) formed insaid shank (40), so that the axial thrust exerted on said rod (6), inthe one or the other direction, generates a component of a forcedirected parallel to the axis of said discs (3, 4) by means of thecontact surfaces between said slider (70) and groove (44), and causessaid axial movements of the movable disc (4) away or closer with respectto the stationary disc (3), in the directions of the groove. 2.(canceled)
 3. The device according to claim 1, wherein two parallel flatsurfaces (60) are made in said lower portion (6B) of said control rod(6), with two of said sliders (70) protruding, symmetrical, therefrom,and in that said shank (40) of the movable disc (4) features alongitudinal slit (42) situated in a median plane of the shank (40),with said slit (42) provided, in the respective side by side faces, withtwo of said grooves (44) and adapted to allow sliding insertion of saidlower portion (6B) of the rod (6) with said flat surfaces (60), as wellas the engagement of said two sliders (70) into the correspondinggrooves (44).
 4. The device according to claim 1, wherein said slider(70) and groove (44) are inclined with respect to the axis of saidstationary (3) and movable (4) discs by an angle comprised between 55°and 60°.
 5. The device according to claim 1, wherein said operatingmeans (8) include a thread (80) made in said upper portion (6A) of saidcontrol rod (6), intended to mesh with a threaded hole (81) formed in athreaded ring (82), with the latter rotatably supported by said rigidtube (2) and adapted to be manually operated to rotate, in one directionor in the other, to determine said axial movements of said control rod(6).
 6. The device according to claim 1, wherein a first annular rim(310) is made in said face (31) of the stationary disc (3), with aninner portion slightly protruding with respect to an external portion,and that a second mirror-like annular rim (410) is made in said face(41) of the movable disc (4), and in that an annular groove (5) with atrapezoidal section is defined between the same first and second annularrims (310, 410), the annular groove being designed to receive saidsealing ring (50) with a complementary trapezoidal cross-section.
 7. Thedevice according to claim 1, wherein said rigid tube (2) and stationarydisc (3) are made integral as a single body.
 8. The device according toclaim 1, wherein the axis of said rigid tube (2) is inclined withrespect to the condition of perpendicularity with the axis of saidstationary disc (3) by an angle between 3° and 6°.
 9. The deviceaccording to claim 1, wherein anti-rotational means (9) are associatedwith said rigid tube (2) for stabilizing the position of the latter andof the stationary disc (3) integral therewith, so that the axis of thesame stationary disc (3), as well as of said movable disc (4), coincidewith that of the said pipeline (200) on a horizontal plane.
 10. Thedevice according claim 9, wherein said anti-rotational means (9) includea flange (90), locked to an upper end (2A) of said rigid tube (2), fromwhich a bar (91) projects radially, adapted to enter a fork (92)fastened to said body (101) of the machine (100).
 11. The deviceaccording to claim 10, wherein said bar (91) is hinged with respect tosaid flange (90) and can rotate upwards to release itself from theconstraint of said fork (92).
 12. A device for the sealing of pipelines,the device comprising: a plugging machine for conveying fluids underpressure affixed to a connector made integral with and communicatingwith the pipeline, perpendicularly to the axis of the latter, with thedevice protruding downward from the plugging machine and inserted withinthe pipeline; a rigid tube supported by a body of the plugging machineand extended therebelow to pass through the connector and insert intothe pipeline with axis almost orthogonal thereto; a stationary discintegral to a lower end of the rigid tube (2), arranged coaxial withrespect to the pipeline and featuring an axial through opening to whichan internal cavity of the tube is joined and which has a face shapedlike a truncated cone; a movable disc arranged coaxial with andcounter-facing the stationary disc with a relative face having atruncated cone profile symmetrical to that of the face of the stationarydisc, with the movable disc featuring an axial shank adapted to beinserted slidably in the axial opening of the stationary disc, so thatthe mutual distance between them can be adjusted; a sealing ring ofelastomeric material with a trapezoidal cross-section interposed betweenthe stationary and movable discs, having its outer diameter dimensionslightly less than an internal diameter of the pipeline in non-operatingcondition (R) when no axial compression is exerted on the discs, withthe stationary and movable discs mutually moved away, the ring beingdesigned to expand radially, in operating condition (W), in a manner asto adhere sealingly to the inner surface of the pipeline as aconsequence of an axial compression exerted by mutual approaching ofeach disc; a control rod slidably inserted in the tube, extended upwardsto come out from the body of the plugging machine and downwards to abutagainst the axial shank of the movable disc; sliding drive meansprovided between the lower portion (6B) of the control rod and the shankof the movable disc, operated by axial translation of the rod so as tomake the shank and the movable disc, rigidly coupled therewith, carryout corresponding axial movements away from or close to the stationarydisc to cause respectively the non-operating (R) and operating (W)conditions of the sealing ring; and operating means, associated to theupper portion of the control rod, provided to determine axial movementsof the control rod; and anti-rotational means (9) are associated withsaid rigid tube (2) for stabilizing the position of the latter and ofthe stationary disc (3) integral therewith, so that the axis of the samestationary disc (3), as well as of said movable disc (4), coincide withthat of the said pipeline (200) on a horizontal plane.
 13. The deviceaccording claim 12, wherein said anti-rotational means (9) include aflange (90), locked to an upper end (2A) of said rigid tube (2), fromwhich a bar (91) projects radially, adapted to enter a fork (92)fastened to said body (101) of the machine (100).
 14. The deviceaccording to claim 12, wherein said bar (91) is hinged with respect tosaid flange (90) and can rotate upwards to release itself from theconstraint of said fork (92).